Administering apparatus comprising a rotational block

ABSTRACT

An administering apparatus including a rotational block which, in the end position of the dosage setting member, permits the rotational dosing movement in a first rotational direction and blocks the rotational dosing movement in a second rotational direction, wherein the rotational block comprises at least one first rotational stopper and at least one second rotational stopper, the first rotational stopper and the second rotational stopper abutting against one another in the end position of the dosage setting member, wherein the at least one first rotational stopper is secured against rotating by the dosage setting member and the at least one second rotational stopper is secured against rotating by the casing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of and claims priority toU.S. application Ser. No. 10/767,837, filed Jan. 29, 2004, which is acontinuation of and claims priority to International Patent ApplicationNo. PCT/CH02/00413, filed on Jul. 22, 2002, which claims priority toGerman Application No. 101 63 328.9, filed on Dec. 21, 2001 and GermanApplication No. 201 12 501.3, filed on Jul. 30, 2001, the contents ofall of which are incorporated herein by reference in their entirety.

BACKGROUND

The invention relates to an administering apparatus for administering afluid product in doses. For example, the invention may provide aninjection apparatus, such as an injection pen or a semi-disposable pen.Alternately, the invention may provide a dosing portion of an inhalationapparatus or an apparatus for oral ingestion or any other type ofapparatus for administering a fluid product.

When administering a product, for example in medical applications,precise dosing of the product is important. In an administeringapparatus such as an injection apparatus, the product is generally dosedusing a dosage setting member which engages a conveying device. Thedosage setting member selects the dosage of product to be delivered andthe conveying device delivers the dosage of product. Problems can arisewith such apparatus when a dosing movement by the dosage setting membercauses a response movement by the conveying device due to theengagement, in particular when such a response movement should beavoided with regard to correct dosing.

SUMMARY

The present invention provides an administering apparatus for deliveringa dosage of product comprising a casing with a reservoir for theproduct, a conveying device, a dosage setting member mechanicallycoupled to the conveying device and a stopper for the dosage settingmember. The conveying device is formed by a driven device and a drivedevice. The driven device is mounted by the casing such that it performsa delivery movement in the form of a delivery stroke in an advancingdirection along a translational axis to deliver a product dosageselected using the dosage setting member. The delivery movement of thedriven device is effected with the drive device, the drive device andthe driven device being coupled. The dosage setting member is coupled tothe driven device such that a rotational dosing movement of the dosagesetting member and the driven device relative to one another about thetranslational axis effects a translational dosing movement of the dosagesetting member along the translational axis relative to the drivendevice and the casing. A translational stopper is provided to limit themovement of the dosage setting member. A rotational block is providedwhich permits the rotational dosing movement in a first rotationaldirection but blocks the rotational dosing movement in a secondrotational direction.

The translational stopper limits the possible movement of the dosagesetting member in one direction along the translational axis. The dosagesetting member is positioned generally opposite and axially facing, inan axial end position, the translational stopper. The axial end positionof the dosage setting member therefore corresponds either to aselectable maximum dosage or minimum dosage, which can be the zerodosage. Accordingly, the translational stopper can be a fronttranslational stopper or a rear translational stopper with respect tothe advancing direction.

If the dosage setting member performs a rotational dosing movement, butis prevented from performing the translational dosing movement resultingfrom being coupled with the driven device, the driven device performs anaxial response movement if it is not otherwise prevented. Preventing theresponse movement results either in damage to the block or to thecoupling between the driven device and the dosage setting member. Such asituation can arise in particular when the dosage setting member assumesthe cited axial end position with respect to the translational stopper.

The rotational block acts in the axial end position of the dosagesetting member, and in the end position restricts the rotational dosingmovement of the dosage setting member to a first rotational direction,by blocking the rotational dosing movement in a second rotationaldirection. The rotational dosing movement which is blocked is that whichwould otherwise axially press the dosage setting member against thetranslational stopper. If the rotational dosing movement is performed inthe second rotational direction and the translational movement isblocked by the translational stopper, then, absent the rotational blockof the present invention, the dosage setting member would be pressedagainst the translational stopper with increasing force. The rotationalblock of the present invention prevents such a pressing force rising toan undesirable level or prevents it from arising at all.

The coupling between the driven device and the dosage setting member maybe realized by the driven device engaging the dosage setting member. Thecoupling may operate to ensure that the driven device and the dosagesetting member may only be moved jointly in the advancing direction. Ifthe drive device acts on the dosage setting member, the dosage settingmember slaves the driven device in the advancing direction. If the drivedevice acts on the driven device, then the driven device slaves thedosage setting member.

The rotational dosing movement effects a relative movement between thedriven device and the dosage setting member. The coupling between thedriven device and the dosage setting member may be configured as a screwjoint. In one embodiment, the screw joint is formed by a direct threadedengagement, wherein the thread axis of the interlocking threads of thedrive device and the dosage setting member coincides with thetranslational axis.

With respect to the advancing direction, the translational stopper maybe a front stopper. The front translational stopper limits the commonmovement of the driven device and the dosage setting member in theadvancing direction. Thus, the front translational stopper may bereferred to as the delivery stopper. Such a delivery stopper may beformed directly by the casing, may be rigidly connected to the casing,or may be immovably mounted by the casing.

Alternately, the translational stopper may be a rear stopper withrespect to the advancing direction. The rear translational stopperlimits the translational dosing movement of the dosage setting member.In accordance with a further embodiment, a delivery stopper and a reartranslational stopper may be provided in combination. The dosage settingmember is positioned axially opposite the respective translationalstopper in the two axial end positions, i.e. the dosage setting memberforms the counter stopper to both translational stoppers. While, in suchan embodiment, the delivery stopper limits the movement of the drivendevice and the dosage setting member by an actual contact, this is notrequired for the rear translational stopper. The rotational block inaccordance with the invention can be formed such that a translationaldosing movement of the dosage setting member, directed towards the reartranslational stopper is blocked before the dosage setting member canaxially push against the rear translational stopper. Providing a dosagesetting member opposite and axially facing a translational stopper, inits axial end position, permits a contact with a force in the axialdirection to occur, but causes a rotational block before contact canoccur. If the translational stopper is a rear stopper, the reartranslational stopper may be formed by the casing or axially andimmovably mounted by the casing. In another embodiment, the drive deviceforms a rear translational stopper, or a rear translational stopper ismounted by the drive device such that it cannot move axially relative tothe drive device.

In accordance with a further embodiment of the present invention, thedosage setting member cannot be rotated about the translational axis,relative to the casing. Instead the driven device may be rotated aboutthe translational axis relative to the casing and the dosage settingmember, for performing the rotational dosing movement. The rotationalblock may be formed either between the dosage setting member and atransfer member or between the dosage setting member and the drivedevice. The transfer member is connected, secured against rotating, tothe driven device and connected, axially immovably, to the casing. Thetransfer member may be formed by a blocking means which prevents thedriven device from moving counter to the advancing direction, relativeto the casing. In this embodiment, the drive device is connected,secured against rotating, to the driven device, but may be axially movedrelative to the driven device, to effect the rotational dosing movementand the delivery stroke.

In a second embodiment, the administering apparatus is configured suchthat the dosage setting member can be rotated about the translationalaxis relative to the casing and the driven device, for performing therotational dosing movement, and the driven device preferably cannot berotated relative to the casing. The rotational block, in suchembodiment, is formed between the dosage setting member and the casing.

The rotational block can be effected using a positive lock, a frictionallock, or any other suitable lock. Using a positive block, the rotationalblock comprises at least two rotational stoppers which form mutuallyfacing stopper areas which reciprocally abut, for the rotationaldirection of the rotational dosing movement which is to be blocked. Theat least two cooperating rotational stoppers are formed such that theypermit and preferably do not impede the rotational dosing movement inthe other rotational direction. The cooperating rotational stoppers maybe elastically flexible with respect to the rotational direction to bepermitted. Preferably, however, the rotational stoppers and the transferof the rotational dosing movement into the translational dosingmovement, are adjusted to each other such that the rotational stopperscooperating for the purposes of blocking are moved apart sufficientlyfast by the non-blocked rotational dosing movement that they do notimpede the rotational dosing movement to be permitted. This may beachieved by adjusting the axial extension of the cooperating rotationalstoppers to the transfer of the rotational dosing movement into thetranslational dosing movement.

The rotational stoppers cooperating for blocking may be formed onsurface areas of the dosage setting member and the body. The rotationalstoppers may be formed radially facing one another. The dosage settingmember and the body, together with the dosage setting member, form thecooperating rotational stoppers.

In a further exemplary embodiment, the dosage setting member and thetranslational stopper each form at least one rotational stopper onabutting areas which axially face one another. The at least tworotational stoppers thus formed abut one another in the axial endposition of the dosage setting member to block the rotational dosingmovement in one rotational direction. The cooperating rotationalstoppers may be formed as protrusions which protrude axially towards oneanother. It is also possible for only one of the cooperating rotationalstoppers to be formed as a protrusion, while the other is formed by arecess into which the protrusion protrudes in the axial end position ofthe dosage setting member.

In an embodiment of the administering apparatus wherein the dosage isselected in discrete increment, and the rotational dosing movementoccurs between discrete rotational angular positions, the cooperatingrotational stoppers may be arranged such that they abut against oneanother or are situated just short of the position in which they abutone another. This position, abutment or just shy thereof, is achievedwhen the dosage setting member and the driven device assume the discreterotational angular positions relative to one another. In this way, theundesirable rotational movement is blocked particularly early. If thecooperating rotational stoppers are formed by a protrusion and a recess,adjusting them in this way enables the protrusion to be accommodatedcompletely in the recess, in the axial end position of the dosagesetting member.

If the product is delivered, using a piston which is advanced in thereservoir in the advancing direction towards an outlet of the reservoir,then the piston and a piston rod form the driven device of the conveyingdevice. The piston rod may be connected fixedly, i.e. permanently, tothe piston. Further, the piston and the piston rod may be formed as aunitary piece. The piston and the piston rod may alternately be formedas separate components, a front end of the piston rod pushing against arear side of the piston to deliver the product.

The drive device may be configured as a dosing and drive device whichassists in selecting the dosage and can be moved axially andtranslationally relative to the casing and rotationally about thetranslational axis. The dosing and drive device may be connected eitherto the driven device or the dosage setting member, secured againstrotating with respect to the translational axis, preferably throughdirect engagement, in order to convert the rotational movement of thedosing and drive device directly into the rotational dosing movement.

In the embodiment described above, the driven device, the dosage settingmember and the dosing and drive device may be connected to one anotherby directly engaging each two or these components or sub-assemblies inpairs, without interposing transfer members. Alternately, interposingone or more transfer members may be done to connect the dosage settingmember and the dosing and drive device.

The dosing and drive device can operate manually, semi-automatically orfully automatically. For manual operation, both the rotational dosingmovement and the translational delivery movement are performed manually.For semi-automatic operation, one of either the rotational dosingmovement or the translational delivery movement is performed manuallywith the other movement being performed using motors or another type offorce application, for example a spring force, when the user hastriggered the corresponding movement using an activating handle. Forfull automatic operation, the dosing movement and the delivery movementare performed using motors or another force, for example a spring force.In this case, only the dosage is selected manually, for example usingone or more buttons, and the delivery movement is triggered by the userusing a corresponding activating handle. In most embodiments, theadministering apparatus of the present invention is equipped with amanual dosing and drive device, which is then referred to as a dosingand activating device. Thus, whenever a “dosing and activating device”is mentioned, it is the manual embodiment which is being referred to.Where a dosing and drive device is mentioned, this is not intended torestrict the invention with respect to being manual, semi-automatic orfully automatic, but rather to comprise each of these embodiments. Theterm “dosing and activating module” is used in connection with all theembodiments of the dosing and drive device.

The dosing and drive device can separately comprise a dosing elementwhich performs the dosing movement and a drive element which performsthe delivery movement. Alternately, however, the dosing movement and thedelivery movement are performed by the same body of the dosing and drivedevice which is therefore also referred to in the following as a dosingand drive element or dosing and activating element.

The product is preferably a fluid, particularly preferably a liquid,having a medical, therapeutic, diagnostic, pharmaceutical or cosmeticapplication. For example, the product may be insulin, a growth hormoneor a thin or thick, pulpy food. The administering apparatus may beemployed in applications in which a user self-administers the producthim/herself, as is common in diabetes therapy. Further, use of theadministering apparatus by trained staff in treating patients is notexcluded.

In the case of an administering apparatus of the present inventioncomprising an injection apparatus, the product can be administered usingan injection cannula such as a nozzle for needle-free injections. Theproduct may be injected or infused subcutaneously, venously, or alsointramuscularly. Alternately, in an embodiment of the administeringapparatus of the present invention comprising an inhalation apparatus,the selected product dosage may be delivered from the reservoir into achamber of the inhalation apparatus and vaporized for inhalation by avaporizing means. Furthermore, oral ingestion or administration via theesophagus may be used. Alternately, the administering apparatus of thepresent invention may be configured for any other suitableadministration to the patient.

The administering apparatus may be configured as semi-disposable. Inthis case, the front casing section is a support for a reservoir modulewhich is disposed of or recycled once the reservoir has been emptied.The rear casing section is a support for a dosing and activating modulewhich may be repeatedly used in conjunction with a new reservoir module.As the reservoir module can also be treated separately as a disposablemodule, it is also a separate subject of the invention. Equally, asystem consisting of an administering apparatus and at least onereservoir module, which can replace the reservoir module of theapparatus once it has been used, forms a subject of the invention. Theduplex design of the administering apparatus, divided into a portionprovided for use only once and a portion provided for repeated use(semi-disposable), is advantageous for injection pens in particular, butis also useful for other administration such as via inhalation, oralingestion, or artificial feeding.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates two portions of a reservoir module in accordance witha first embodiment of the present invention;

FIG. 2 illustrates the reservoir module formed by the two portions ofFIG. 1;

FIG. 3 illustrates a perspective view of an injection apparatusincluding the reservoir module of FIG. 2, in accordance with the firstembodiment, in a longitudinal section;

FIG. 4 illustrates a portion of the injection apparatus of FIG. 3;

FIGS. 5 a-5 c illustrate a mechanism holder of the reservoir module, ina longitudinal section and two views;

FIGS. 6 a-6 d illustrate a blocking device for a piston rod, mounted bythe mechanism holder;

FIGS. 7 a, 7 b illustrate a piston rod in a longitudinal section and afront view;

FIGS. 8 a-8 c illustrates a latching block in a longitudinal section, aview and a top view;

FIG. 9 illustrates a second embodiment of an injection apparatus of thepresent invention;

FIG. 10 illustrates the cross-section A-A of FIG. 9;

FIG. 11 illustrates the cross-section B-B of FIG. 9;

FIG. 12 illustrates the cross-section C-C of FIG. 9;

FIG. 13 illustrates the cross-section D-D of FIG. 9;

FIG. 14 illustrates a perspective view of the mechanism holder of thesecond embodiment of the present invention;

FIG. 15 illustrates the mechanism holder of FIG. 14, in a view;

FIG. 16 illustrates the cross-section A-A of FIG. 15;

FIG. 17 illustrates a perspective view of the dosage setting member ofthe second embodiment;

FIG. 18 illustrates a longitudinal view of the dosage setting member ofFIG. 17;

FIG. 19 illustrates the dosage setting member of FIG. 17;

FIG. 20 illustrates a top view of the dosage setting member of FIG. 17;

FIG. 21 illustrates a portion of the injection apparatus in accordancewith FIG. 3; and

FIG. 22 illustrates a portion of the injection apparatus in accordancewith FIG. 9.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate a reservoir module 10 for use with anadministering apparatus of the present invention. As shown in FIG. 1,the reservoir module 10 is formed by a reservoir part 1 and a mechanismholder 3. The reservoir part 1 and the mechanism holder 3 may beconnected in any suitable manner to form the reservoir module 10. Apiston rod 4 protrudes on an end of the mechanism holder 3 facing awayfrom the reservoir part 1, into the mechanism holder 3. The piston rod 4is mounted by the mechanism holder 3 such that it can shift in anadvancing direction pointing along the longitudinal axis L of the pistonrod 4, towards a front end of the reservoir part 1 facing away from themechanism holder 3. The reservoir part 1 is substantially a hollowcylinder which has a circular cross-section and comprises a connectingregion at its front end for connecting to a needle holder for aninjection needle. The reservoir part 1 accommodates a reservoircontainer.

FIG. 3 illustrates an administering apparatus with the present inventioncomprising an injection apparatus. As shown, the reservoir containeraccommodated by the reservoir part 1 is an ampoule 2. An outlet at thefront end of the ampoule 2 is sealed fluid-tight by a membrane. When aneedle holder is fastened to the front end of the reservoir part 1, arear portion of the injection needle pierces the membrane, such that afluid connection between the tip of the hollow injection needle and thereservoir 2 is established. A piston is accommodated in the ampoule 2such that it can shift in the advancing direction towards the outletformed at the front end of the ampoule 2. Shifting the piston in theadvancing direction displaces product out of the ampoule 2 and deliversit through the outlet and the injection needle.

The piston is advanced by the piston rod 4 which pushes against thepiston via its front end and thus moves the piston in the advancingdirection when advanced. The piston rod 4 is held by the mechanismholder 3 such that it can be moved in the advancing direction once acertain resistance, described below, has been overcome. The mechanismholder 3 further holds the piston rod 4 such that it cannot be movedcounter to the advancing direction. The piston rod 4 is prevented frommoving backwards, counter to the advancing direction, by a blockingdevice 8. The blocking device 8 is axially fixed by the mechanism holder3. As shown, the blocking device 8 is held in the mechanism holder 3such that it cannot be moved in and counter to the advancing direction.The mechanism holder 3 permits the blocking device 8 to be rotated aboutthe longitudinal axis L. The blocking device 8 also generates theresistance to be overcome to move forward.

The blocking device 8 is separately shown in FIGS. 6 a-6 d. The blockingdevice 8 is formed by an annular element which, rotatable about thelongitudinal axis L, abuts the mechanism holder 3 between two facing,spaced collars 3 b. The mounting of the blocking device 8 in themechanism holder 3 can be seen in FIG. 5. The collars 3 b protruderadially inwards from an inner surface of the mechanism holder 3. Thecollars 3 b form a fixing means for axially fixing the blocking device8.

Returning to FIG. 3, a dosage setting member 9 is accommodated in themechanism holder 3. The dosage setting member 9, as shown, is formed asa threaded nut and is in threaded engagement with an outer thread of thepiston rod 4. However, the dosage setting member 9 may be formed in anysuitable manner. The dosage setting member 9 is secured against rotatingby the mechanism holder 3, but is guided such that it can move axiallyand linearly in and counter to the advancing direction. The piston rod 4and the dosage setting member 9 together form a spindle drive forselecting the product dosage to be administered.

The ampoule holder 1 and the mechanism holder 3 are connected to oneanother, secured against rotating and shifting, and, together form thereservoir module 10 of the injection apparatus. The reservoir module 10comprises the piston rod 4 held by the mechanism holder 3 with theblocking device 8, and the dosage setting member 9. The ampoule holder 1and the mechanism holder 3 together form a front casing section of theinjection apparatus. A rear casing section 11 is connected to said frontcasing section 1′ in a positive lock. The rear casing section 11 formsthe support for a dosing and activating element 12 and, together withthe dosing and activating element 12 and, in some embodiments, parts ofa latching means and other parts, forms a dosing and activating module30 of the injection apparatus.

A plurality of components select the product dosage and activate theadministering apparatus. These include the dosage setting member 9, thepiston rod 4 and the blocking device 8. Further included is a dosing andactivating device, itself comprising a plurality of components. Thedosing and activating device comprises the dosing and activating element12 and a counting and indicating means 17. The counting and indicatingmeans 17 counts and optically indicates the selected product dosage. Ofcourse, the dosage may be indicated by the counting and indicating means17 in a manner other than optically, for example audibly. While thereservoir module 10 is designed as a disposable module, the dosing andactivating module 30 is intended for repeated use.

For selecting the product dosage, or dosing, the dosing and activatingelement 12 can be rotated about the longitudinal axis L. The dosing andactivating element 12 is mounted by the rear casing section 11 such thatit can linearly shift along the longitudinal axis L, in and counter tothe advancing direction. The dosing and activating element 12 iscylindrical and generally hollow. The dosing and activating element 12at least partially surrounds the piston rod 4 via a front section. Arear section of the dosing and activating element 12 protrudes outbeyond a rear end of the casing section 11. A rod-shaped dosing slavingmeans 13 is inserted into the dosing and activating element 12 from therear, as far as a collar of the dosing and activating element 12protruding radially inwards. At the rear end, a closure 14 is insertedinto the dosing and activating element 12, approximately as far as thedosing slaving means 13. The dosing slaving means 13 is axially fixedrelative to the dosing and activating element 12 between the radiallyprotruding collar of the dosing and activating element 12 and theclosure 14. The dosing slaving means 13 is also connected, securedagainst rotating, to the dosing and activating element 12. For dosing,the dosing slaving means 13 protrudes into the piston rod 4 from therear. The piston rod 4 is at least partially hollow to receive thedosing slaving means 13. As shown in FIG. 4, the piston rod 4 comprisesa connecting section 4 a which engages with the dosing slaving means 13such that the piston rod 4 and the dosing slaving means 13, andtherefore also the dosing and activating element 12, cannot be rotatedrelative to one another about the common longitudinal axis L, but can bemoved relative to each other along the longitudinal axis L, in andcounter to the advancing direction. For this purpose, the connectingsection 4 a is formed as a linear guide for the dosing slaving means 13.

A restoring means 16 elastically tenses the dosing and activatingelement 12 counter to the advancing direction, into the initial positionshown in FIGS. 3 and 4. In the initial position, the product can bedosed by rotating the dosing and activating element 12 about thelongitudinal axis L. From the initial position, the selected productdosage can be delivered by axially shifting the dosing and activatingelement 12. As shown, the restoring means 16 is formed by a spiralspring acting as a pressure spring, which is accommodated in an annulargap around the dosing and activating element 12. The restoring means 16is axially supported between a collar of the casing section 11protruding radially inwards and a collar of the dosing and activatingelement 12 facing opposite and protruding radially outwards. While aspiral spring is shown, the restoring means 16 may be configured in anysuitable manner.

The blocking device 8 fulfils a double function. It ensures via itsblocking elements 8 a that the piston rod 4 cannot be retracted, counterto the advancing direction, relative to the mechanism holder 3 andrelative to the piston accommodated in the ampoule 2. The blockingdevice 8 further functions as a brake. The blocking device 8 preventsthe piston rod 4 from moving forward during the dosing process in whichthe dosage setting member 9 is moved axially, counter to the advancingdirection, towards the dosing and activating element 12.

In the initial position shown in FIGS. 3 and 4, before dosing, thedosage setting member 9 abuts against a delivery stopper 3 c, shown inFIG. 5, formed by the mechanism holder 3, in the advancing direction.The piston rod 4 is in contract with the piston. For dosing, the dosagesetting member 9 is moved away from the delivery stopper 3 c towards thedosing and activating element 12 by the threaded engagement with thepiston rod 4 and the linear guide from the mechanism holder 3. Thisreduces a slight distance between a rear stopper area of the dosagesetting member 9 and a front stopper area of the dosing and activatingelement 12, but increases a slight distance between a front stopper areaof the dosage setting member 9 and the delivery stopper 3 c. Thedistance between the dosage setting member 9 and the delivery stopper 3c is the path length by which the dosage setting member 9 and, due tothe threaded engagement, the piston rod 4 are moved in the advancingdirection during the delivery movement of the dosing and activatingelement 12. The delivery stopper 3 c forms a front translationalstopper. During the delivery movement, the piston rod 4 pushes via itsfront end, which is formed by a plunger body connected to the piston rod4 such that it cannot move in or counter to the advancing direction,against the piston and pushes the piston forwards in the advancingdirection towards the outlet of the ampoule 2. The longitudinal axis Lforms the rotational and translational axis of the movements which areperformed to dose and deliver the product.

The distance between the dosage setting member 9 and the dosing andactivating element 12 during the dosing process when the dosage settingmember 9 abuts against the delivery stopper 3 c corresponds to themaximum product dosage which can be selected and delivered. The strokemovement of the dosing and activating element 12 is of equal length foreach delivery. Dosing merely sets the distance between the dosagesetting member 9 and the delivery stopper 3 c and, thus, the path lengthwhich can be jointly traveled by the dosing and activating element 12and the dosage setting member 9 during delivery. The dosing andactivating element 12 forms a rear translational stopper 12 c whichlimits the translational dosing movement of the dosage setting member 9and thus defines the maximum delivery stroke which may be set.

The blocking device has a braking function and, therefore, a brakingengagement exists between the piston rod 4 and the blocking device 8.FIGS. 6 a through 6 d and FIGS. 7 a and 7 b illustrate the blockingdevice 8 and its engagement with the piston rod 4. The blocking device 8comprises two braking elements 8 b for the braking engagement, which, asshown, are each formed by an elastically flexing catch, like theblocking elements 8 a before them. In the embodiment shown, the blockingdevice 8 is formed by an annular element from which four elastic catchesaxially project on an abutting side. The catches are arranged in auniform distribution over the circumference of the annular element. Twomutually opposing catches form the blocking elements 8 a and the othertwo catches, likewise arranged mutually opposing, form the brakingelements 8 b. Alternately, the blocking device 8 may be formed in anysuitable configuration. Likewise, if provided, each of the blockingelements 8 a and braking elements 8 b may be formed in any suitablemanner.

The piston rod 4 accordingly includes two returning blocking means 6,which are formed on opposing sides on the outer surface of the pistonrod 4 and extend in the longitudinal direction. The piston rod 4 furtherincludes two advancing braking means 7, which likewise extend in thelongitudinal direction of the piston rod 4 on mutually opposing sides.The thread of the piston rod 4 for threaded engagement of the piston rod4 with the dosage setting member 9 is formed by four remaining threadedsections 5 which extend over almost the entire length of the piston rod4. The returning blocking means 6 and the advancing braking means 7 areeach formed by a row of teeth. However, while the teeth of the returningblocking means 6 are formed as serrated teeth, narrowing in theadvancing direction and comprising blocking areas pointing backwards andextending transverse to the advancing direction, the rows of teeth whichform the advancing braking means 7 do not comprise blocking areaspointing forwards having a comparable blocking effect. The teeth of theadvancing braking means 7 each exhibit a softer tooth profile ascompared to the returning blocking means 6. Of course, the returningblocking means 6 and the advancing braking means 7 may alternately beformed in any suitable manner. The braking engagement between theblocking device 8 and the advancing braking means 7 of the piston rod 4is not intended to prevent the piston rod 4 from being advanced, butmerely to make it more difficult, thereby ensuring that the piston rod 4is not moved in the advancing direction during dosing. The front sidesof the teeth of the advancing braking means 7 and the rear sides of thebraking elements 8 b, which contact the front sides of the teeth of theadvancing braking means 7, are configured such that a threshold forcewhich is not reached during dosing has to be exceeded to overcome thebraking engagement. This threshold force exceeds the force required tomove the teeth of the returning blocking means 6 over the blockingelements 8 a in the advancing direction. The threshold force ispreferably at least twice as large as the initial frictional forcebetween the returning blocking means 6 and the blocking elements 8 a.The frictional force between the latter increases gradually between twoconsecutive blocking engagements during the advancing movement. Thethreshold force of the braking engagement, by contrast, has to beapplied from one blocking engagement to the next, immediately at thebeginning of the advancing movement, in each blocking engagement.Regardless, the threshold force should not, be so large as to distractthe user during delivery.

An undesired advancing movement by the piston rod responsive to themovement by the dosage setting member 9 when selecting the dosage may beprevented by the blocking engagement of the blocking device 8 alone.However, such a movement is more reliably prevented in conjunction withthe braking engagement than by relying the blocking engagement alone.

The connection between the reservoir module 10 and the dosing andactivating module 30 is a positive lock. A latching engagement existsbetween the mechanism holder 3 and the casing section 11 which preventsrelative movement in the axial direction. Beyond the latchingengagement, the front casing section 1′ and the rear casing section 11are guided axially and linearly directly onto one another to preventrelative rotating when connected. The axial guides 3 d of the mechanismholder 3, which together with one or more corresponding engagementelements of the rear casing section 11 form the linear guide, can beseen in FIGS. 5 a-5 c. As shown, the axial guides 3 d are formed byguide areas on guide ribs. The axial guides 3 d may alternately beformed by guide areas in axially extending recesses, thus forming axialguide channels. The guide ribs are axially tapered, such that insertionfunnels leading into the guide channels are formed for the one or moreengagement elements of the rear casing section 11. To better center thecasing sections 1′ and 11 at the beginning of connecting, the guide ribsare also tapered in the radial direction. The one or more engagementelements of the rear casing section 11 may be formed like the axialguides 3 d on the inner surface area of the rear casing section 11.

A latching engagement exists between a first, female latching element 3a of the mechanism holder 3 and a latching ring 20 which is connected tothe rear casing section 11 such that it can move radially but notaxially. The latching ring 20 forms a second, male latching element 21which radially engages directly with the first latching element 3 a. Alock/latch connection exists between the first latching element 3 a andthe second latching element 21 which prevents the reservoir module 10and the dosing and activating module 30 from moving axially relative toone another.

Returning to FIGS. 3 and 4, the second latching element 21 in latchingengagement with the first latching element 3 a. The first latchingelement 3 a is formed by an annular stay and a groove which runs aroundthe outer surface of the mechanism holder 3. The annular stay forms arear side wall of the groove. The second latching element 21 is formedby a cam which protrudes radially inwards from the inner surface of thelatching ring 20 and which in the latching engagement is pushed radiallyinwards over an inner surface area of the rear casing section 11,protruding into the accommodating latching element 3 a, by a restoringmeans 24. The latching ring 20 is supported in the radial direction onan inner surface area formed by the rear casing section 11, by therestoring means 24, such that the restoring means 24 pushes against theouter surface of the latching ring 20 roughly in a radial extension ofthe latching element 21. The latching ring 20 surrounds the mechanismholder 3 and can be moved radially back and forth against the restoringforce of the restoring means 24, such that the second latching element21 can be moved in and out of latching engagement with the firstlatching element 3 a. The rear casing section 11 forms a tight slidingguide for the radial movement of the latching ring 20. On its sideradially opposite the latching element 21, the latching ring 20 forms anunlatching button 22. To radially guide the restoring means 24, formedas a pressure spring, a guide cam projects radially from the outersurface area of the latching ring 20 facing away from the latchingelement 21.

Two blocking cams 23 are provided to prevent a radial movement of thesecond latching element 21. Such radial movement could otherwise resultin the latching engagement being released. The blocking cams 23 pressradially outwards against a latching block 25 and project from the outersurface area of the latching ring 20, in the circumferential directionon both sides of said guide cam and axially behind the guide cam. Theblocking cams 23 thus abut against the latching block 25. The latchingengagement between the latching elements 3 a and 21 is thus secured bythe latching block 25. The latching engagement is secured in eachposition of the dosing and activating element 12, except for a releasingposition which the dosing and activating element 12 assumes at the endof its delivery movement. The releasing position coincides with theforemost shifting position of the dosing and activating element 12 whenit abuts the dosage setting member 9 during its delivery movement andthe dosage setting member 9 abuts against the delivery stopper 3 c ofthe mechanism holder 3. Providing the dosing and activating module 30 isnot yet connected to the reservoir module, a mechanical stopper for thedosing and activating element 12 is formed by a stopper element 31 ofthe dosing and activating device. In the embodiment shown, a resetholder ring which resets the indicator 17 forms the stopper element 31.The dosing and activating element 12 abutting against the stopperelement 31 defines the releasing position of the dosing and activatingelement 12. The releasing position defined by the stopper element 31corresponds to that defined by the dosage setting member 9 abutting thedelivery stopper 3 c.

FIGS. 8 a through 8 c illustrate the latching block 25. As shown, thelatching block 25 is formed by a blocking slider as a unitary piece. Thelatching block 25 comprises a plate-shaped main body which extendsaxially when assembled, as for example shown in FIG. 4. At one end, astay 26 projects at approximately right angles from the main body. Whenassembled, the stay 26 extends radially approximately as far as thedosing and activating element 12. The stay 26 fastens the latching block25 to the dosing and activating element 12 which, for this purpose,comprises two annular stays formed axially spaced on an outer surfacearea. The two annular stays form the slaving means 15 a and 15 b. Thefront slaving means 15 a also forms the support collar for the restoringmeans 16. The latching block 25 is tightly enclosed axially on bothsides by the two slaving means 15 a and 15 b. The latching block 25protrudes into the annular space formed between the two slaving means 15a and 15 b via its stay 26.

At a front end facing away from the stay 26, the main body of thelatching block 25 is provided with an axial recess 27 which is opentowards the front end of the latching block 25. Blocking tongues 28extending axially on both sides of the recess 27 are thus formed. Theblocking cams 23 of the latching ring 20 are arranged such that each ofthe blocking cams 23 pushes against one of the blocking tongues 28,providing the dosing and activating element 12 does not assume thereleasing position. When the latching block 25 moves axially, therestoring means 24 for the latching element 21 extends through the axialrecess 27. Indentation recesses 29 are furthermore formed in the mainbody of the latching block 25, and define the releasing position of thedosing and activating element 12. One indentation recess 29 is providedfor each of the blocking cams 23. The position of the indentationrecesses 29 is selected such that they only overlap the blocking cams23, and thus allow the blocking cams 23 to be inserted, when the dosingand activating element 12 has been advanced into its releasing position.

Of course, in the arrangement shown, a single blocking cam 23 could alsobe provided and the latching block 25 accordingly comprise only oneindentation recess 29 and as well as only one blocking tongue 28. Thelatching block 25 may alternately be produced together with the dosingand activating element 12 as a unitary piece. Further, any othersuitable configuration for the latching block 25 may be used. Withrespect to the installation length of the latching block 25, thelatching block 25 is supported, on its outer side facing away from thelatching element 21, on an inner surface area of the casing 11. Thisincreases the stability of securing the latching engagement. The casing11 preferably forms an axial guide for the latching block 25.

The functionality of the injection apparatus is described in thefollowing, wherein it is assumed that a new reservoir module 10 and adosing and activating module 30 which has already been used at leastonce are assembled and a product is then delivered for the first time.

The dosing and activating module 30 and the new reservoir module 10 arealigned axially with respect to one another, such that their twolongitudinal axes are flush with one another. The reservoir module 10 isinserted via its rear end into the casing 11, which is open to thefront, of the dosing and activating module 30. This centers the casingsection 1′ and the casing section 11 on the tapered ends of the guideribs 3 d of the mechanism holder 3. The two casing sections are guidedaxially and linearly onto one another in a rotational angular positionpre-set by the linear guide, until the casing sections 1′ and 11 assumea connecting end position in which the latching engagement of thelatching elements 3 a and 21 can be established.

The dosing and activating element 12 is locked in pre-set rotationalangular positions relative to the rear casing section 11. The linearguide of the casing sections 1′ and 11 and the rotational angularlocking positions of the dosing and activating element 12 are adjustedto one another such that the engagement, secured against rotating,between the dosing and activating element 12 and the piston rod 4 isestablished in each locking position of the dosing and activatingelement 12 and each rotational angular position in which the casingsections 1′ and 11 are linearly guided onto one another.

If the dosing and activating element 12 is situated in an axial positionrelative to the casing section 11 which is behind the releasingposition, the latching element 21 is held in its radially innermostposition by the latching block 25. In this position of the latchingelement 21, the dosing and activating module 30 and the reservoir module10 cannot be slid onto each other up to the connecting end position andtherefore also cannot be connected to one another, as the annular stayformed on the outer surface of the mechanism holder 3, which forms apart of the first latching element 3 a, comes to rest abutting againstthe second latching element 21 first.

The annular stay may be reduced to a short radial protrusion in thetangential direction, if it is ensured that the casing sections 1′ and11 can only be assembled in the rotational angular position in whichsuch a protrusion and the second latching element 21 come to rest in anaxial flush. The annular stay or radial protrusion may also form thefirst latching element 3 a. The first latching element 3 a allows theconnection between the reservoir module 10 and the dosing and activatingmodule 30 to be established only when the dosing and activating element12 assumes its releasing position. If this condition is fulfilled, thedosing and activating element 12 ensures, when the connection betweenthe reservoir module 10 and the dosing and activating module 30 isestablished, that the dosage setting member 9 is situated in its dosingzero position, abutting the delivery stopper 3 c of the mechanism holder3.

To fulfill the above-described condition, wherein the dosing andactivating element 12 assumes its released position, the user pushes thedosing and activating element 12 axially forwards relative to the rearcasing section 11 approximately as far as the releasing position. Inthis relative position between the rear casing section 11 and the dosingand activating element 12, the blocking cams 23 may be moved into theindentation recesses 29 of the latching block 25. The user therefore notonly pushes the dosing and activating element 12 but also pushes thesecond latching element 21 out of latching engagement by using theunlatching button 22. The reservoir module 10 may then be moved axiallyover the annular stay of the first latching element 3 a and insertedfurther into the rear casing section 11. The user can release theunlatching button 22. When the second latching element 21 overlaps thefirst latching element 3 a, the second latching element 21 snaps intothe accommodating first latching element 3 a due to the force of therestoring means 24, such that the latching engagement is established.The reservoir module 10 and the dosing and activating module 30 are thenconnected to each other in a defined way with respect to the position ofthe dosage setting member 9 and the piston rod 4. If the dosage settingmember 9 still exhibited a slight distance from the delivery stopper 3 cbefore the latching engagement is established, this distance isgenerally eliminated by the action of the dosing and activating element12 required to establish the connection. A resultant delivery of productcan be accepted for priming the injection needle. This preferably resetsthe counting and indicating means 17 to zero.

In the defined initial, the user can dose the product. The product isdosed by rotating the dosing and activating element 12 about thelongitudinal axis L and relative to the casing section 11. As the dosingslaving means 13 is connected to the dosing and activating element 12,secured against rotating, and engages with the piston rod 4, securedagainst rotating, the dosing and activating element 12 slaves the pistonrod 4 during its rotational dosing movement. Due to the threadedengagement between the piston rod 4 and the dosage setting member 9 andthe linear guide of the dosage setting member 9 by the mechanism holder3, the dosage setting member 9 performs an axial, translational dosingmovement, pre-set by the thread pitch of the reciprocal threadedengagement, towards the dosing and activating element 12. The reartranslational stopper 12 c formed by the dosing and activating element12 limits the translational dosing movement of the dosage setting member9 and defines the maximum delivery stroke which may be set.

The counting and indicating means 17 counts the dosage unitscorresponding to the rotational angular position of the dosing andactivating element 12 and indicates it optically.

Once the desired product dosage has been selected, the dosing process iscompleted. The selected product dosage is delivered by the deliverymovement, pointing in the advancing direction of the piston, of thedosing and activating element 12. During the delivery movement, thedosing and activating element 12 abuts against the dosage setting member9 and slaves it. When the dosage setting member 9 abuts against thedelivery stopper 3 c of the mechanism holder 3 during the deliverymovement, the delivery movements of the dosing and activating element 12and the delivery of product are completed. Once the user releases thedosing and activating element 12, the dosing and activating element 12is moved counter to the advancing direction and returned to a newinitial position for dosing and delivering the product again, by therestoring means 16. The counting and indicating means 17 is preferablycoupled to the dosing and activating element 12 such that it resets tozero after delivery of the product. Further, the counting and indicatingmeans 17 may be configured such that it counts and indicates the totalproduct amount already delivered and thus the residue product amountremaining in the ampoule 2.

To detach the reservoir module 10 from the dosing and activating module30, the dosing and activating element 12 is advanced to the releasingposition, i.e. until it abuts against the dosage setting member 9. Theuser releases the latching engagement by pushing the unlatching button22 and separates the reservoir module 10 from the dosing and activatingmodule 30.

FIGS. 9 to 13 illustrate a second embodiment of an injection apparatusin accordance with an administering apparatus of the present invention.The injection apparatus of the second embodiment corresponds with thatof the first embodiment with respect to the latch and latching block 25,such that reference is made in this regard to the description of thefirst embodiment. The latching block 25 of the second embodimentreflects that of the first embodiment with respect to all its functionaldetails. The same applies to the latching elements 3 a and 21.

The latching ring 20 and the position of the blocking cams 23 relativeto the latching element 21 and relative to the latching block 25 in theinitial state of the apparatus is shown in the cross-sections of FIGS.10, 11 and 12, to which reference is made in this regard, also asrepresentative for the first embodiment.

The injection apparatus of the second embodiment differs from the firstembodiment in the engagement and the progression of movement of thecomponents involved in dosing. Furthermore, the mechanism holder, inaddition to the functions of the mechanism holder of the firstembodiment, positions the dosage setting member in discrete rotationalangular positions which may be changed relative to the mechanism holder,for the purpose of dosing. The blocking means of the second embodiment,by contrast, is embodied more simply than that of the first embodiment.For the most part, the differences as compared to the first embodimentwill be described in the following, wherein for components which areidentical in their basic function to the components of the same name inthe first embodiment but differ in details, numbers in the thirties withthe same end digit, or exactly the same reference numerals as in thefirst embodiment, are used. Where no statements are made regarding thesecond embodiment, the corresponding statements regarding the firstembodiment shall apply.

In the second embodiment, the dosing and activating element 32, whichcan be moved axially and linearly relative to the rear casing section 11and rotated about the longitudinal axis L, is connected to the dosagesetting member 39, secured against rotating. The dosing and activatingelement 32 and the dosage setting member 39 can be moved in and counterto the advancing direction, relative to one another and relative tocasing sections 1′ and 11. The piston rod 4 is held by a mechanismholder 3, secured against rotating. In cooperation with blockingelements of the blocking device 38, formed on the mechanism holder 3 asa unitary piece, the returning blocking means 6, which is functionallyidentical to the first embodiment, prevents the piston rod 4 from movingcounter to the advancing direction, but allows it to move in theadvancing direction. The blocking elements forms both the returningblock and the rotational block for the piston rod 4. Furthermore, aspreviously in the first embodiment, the dosing and activating element 32forms a sliding guide for the piston rod 4.

During dosing, the dosing and activating element 32 performs the samerotational dosing movement as the dosing and activating element 12 ofthe first embodiment. However, as the engagement is secured againstrotating, the dosage setting member 39 is slaved during the rotationaldosing movement. The threaded engagement between the piston rod 4 andthe dosage setting member 39 is again comparable to that of the firstembodiment. Due to the rotational dosing movement and the threadedengagement with the piston rod 4, a stopper 39 c formed by the dosagesetting member 39 is moved, during dosing, counter to the advancingdirection, towards a front end of the dosing and activating element 32.As opposed to the first embodiment, the dosage setting member 39 thuscompletes a rotational dosing movement and a translational dosingmovement relative to the front casing section during dosing, while thepiston rod 4 remains stationary. Once dosing has been completed, thedelivery movement of the dosing and activating element 32 advances thepiston rod 4 by the path length which corresponds to the slight distancebetween a stopper area of the dosage setting member 39 and the deliverystopper 3 c of the mechanism holder 3, set by the dosing.

The translational dosing movement of the dosage setting member 39 islimited counter to the advancing direction by a rear translationalstopper 11 c which is formed directly by the rear casing section 11. Therotational and translational axis of the components involved in dosingand delivering the product forms the longitudinal axis L.

As in the first embodiment, the front casing section 1′ forms a slidingguide for the dosage setting member 39. In order to form the slidingguide, an inner surface area of the mechanism holder 3 and an outersurface area of the dosage setting member 39 are in sliding contact witheach other. The dosing and activating element 32 engages with an innersurface area of the dosage setting member 39, to form the connection,secured against rotating, between the dosage setting member 39 and thedosing and activating element 32.

In the second embodiment, the piston rod 4 comprises no braking means ofits own beyond the returning blocking means 6. Rather, the front sidesof the serrated teeth of the returning blocking means 6 also form thebraking means. The piston rod 4 of the second embodiment can, however,be replaced by the piston rod 4 of the first embodiment. Accordingly,the mechanism holder 3 of the second embodiment may form at least onebraking element, and preferably both braking elements, of the firstembodiment.

FIGS. 14 to 16 illustrate the mechanism holder 3 of the secondembodiment in a perspective representation, a side view and in thecross-section A-A indicated in the side view. As in the firstembodiment, the mechanism holder 3 is embodied as a unitary sleeve part,for example as a plastic injection molded part. It comprises a bulge 3 eon the outer surface of a front sleeve section. The front sleeve sectionis plugged into the reservoir part 1 and locked non-detachably, at leastfor the user, to the reservoir part 1 by the bulge 3 e.

The latching element 3 a is formed on a middle sleeve section of themechanism holder 3, as in the first embodiment. A rear sleeve section,connected to the latching element 3 a, forms a plurality of axial guides3 d on its outer circumference. The axial guides 3 d are formed by guideribs which protrude radially on the outer circumference of the rearsleeve section. The axial guides are formed by the axially extending,straight side walls of said guide ribs, such that, as in the firstembodiment, axial guiding channels are obtained. The guide ribs protrudefrom the middle sleeve section, approximately as far as the rear end ofthe mechanism holder 3, where they taper axially. The axial guide 3 dlinearly guides the rear casing section 11 when the reservoir module 10is connected to the dosing and activating module 30. As can be seen inFIGS. 9 and 11, engagement elements 11 d project radially inwards fromthe inner surface area of the rear casing section 11. One engagementelement 11 d protrudes into each of the axial guides 3 d and is linearlyguided by the axial guide 3 d when the front casing section 1′ and therear casing section 11 are slid into one another. This restrictsrelative rotating between the front casing section 1′ and the rearcasing section 11 during engagement, secured against rotating, betweenthe dosing and activating element 32 and the dosage setting member 39.

As the guide ribs taper axially at their rear ends, and the guidechannels are thus widened into insertion funnels, centering between thefront casing section 1′ and the rear casing section 11, for the purposeof connecting, is simplified. The guide ribs also taper at their endsradially with respect to the surface area of the mechanism holder 3,which simplifies centering the casing sections 1′ and 11 into arotational angular position pre-set by the axial guide 3 d, relative toone another.

Just as the front casing section 1′ and the rear casing section 11 areprevented from rotating relative to one another during connection, thedosage setting member 39 is also fixed with respect to its rotationalangular position relative to the front casing section 1′. The dosagesetting member 39 is detachably fixed to allow the rotational movementof the dosage setting member 39 necessary for dosing. To enable thedosing movement of the dosage setting member 39 but prevent an undesireddosing movement by establishing the connection between the front casingsection 1′ and the rear casing section 11, the dosage setting member 39is fixed by the mechanism holder 3 in discrete rotational angularpositions, by a releasable locking connection.

FIGS. 17 to 20 show individual representations of the dosage settingmember 39. For forming the locking connection, a number of lockingrecesses 39 g are formed on the outer surface area of the dosage settingmember 39, distributed in generally regular intervals over thecircumference of the dosage setting member 39. Each of the lockingrecesses 39 g is formed by a straight, axially extending furrow having arounded contour running in its cross-section. Of course, the lockingrecesses 39 g may alternately be formed in any suitable manner.

Returning to FIGS. 15 and 16, the mechanism holder 3 is provided withtwo locking projections 3 g. The two locking projections 3 g projectradially inwards from an inner surface area of the mechanism holder 3 inthe rear sleeve section of the mechanism holder 3. The two lockingprojections 3 g, as shown, are arranged diametrically opposed to oneanother. The respective surface region of the mechanism holder 3, onwhich one of the locking projections 3 g is formed, forms a springelement 3 f which is elastically flexible in the radially direction. Dueto the elastic flexibility and the rounded shape of the lockingprojections 3 g, in conjunction with the rounded profile of the lockingrecesses 39 g, the locking engagement between the locking projections 3g and the opposing locking recesses 39 g may be released. Releasing thelocking engagement between the locking projections 3 g and the opposinglocking recesses 30 g allows the dosage to be selected. The lockingengagement is designed, however, such that the dosage setting member 39is rotationally angularly fixed and undesired dosing movement of thedosage setting member 39 is prevented when the front casing section 1′and the rear casing section 11 are connected and when the rotationalcoupling between the dosing and activating element 32 and the dosagesetting member 39 is established. The locking connection between themechanism holder 3 and the dosage setting member 39 has the advantageousside effect of a tactile signal during dosing. To maintain theelasticity of the spring element 3 f, the rear sleeve section of themechanism holder 3 is cut away in the surface region, such that thespring element 3 f is maintained as an annular segment extending in thecircumferential direction which is axially free on both sides.

Returning to FIGS. 17 through 20, axial guides 39 d are provided for theengagement, secured against rotating, between the dosage setting member39 and the dosing and activating element 32. The dosing and activatingelement 32 is provided with at least one engagement element, in order toobtain the axial linear guide, i.e. the rotational block, between thedosing and activating element 32 and the dosage setting member 39. Theaxial guides 39 d are again guide channels formed by a number of guideribs extending axially in a straight line. Each of the guide ribs tapersaxially and radially at its rear end facing the dosing and activatingelement 32, thus simplifying centering between the dosing and activatingelement 32 and the dosage setting member 39, when the engagement,secured against rotating, is established. The same design is thereforeused for the axial linear guide of the dosage setting member 39 and thedosing and activating element 32 as for the axial linear guide of thecasing sections 1′ and 11.

The dosing setting member 39 is further provided with a dosing thread 39a and a delivery stopper 39 c. Two rotational blocks are provided forthe dosage setting member 39 which are active in the two axial endpositions of the dosage setting member 39. Reference is additionallymade in this regard to FIG. 22.

To prevent retraction of the piston rod 4 in response to a rotationaldosing movement by the dosage setting member 39, rotational stoppers 39h are formed at a front end of the dosage setting member 39. In thefront position, which the dosage setting member 39 assumes directlyafter the product is delivered or before the dosage is selected, therotational stoppers 39 h engage with rotational counter stoppers 3 hformed on the mechanism holder 3 (FIG. 16). The rotational stoppers 39 haxially project from a front abutting side of the dosage setting member39, and the rotational counter stoppers 3 h protrude from an axiallyfacing abutting area of the mechanism holder 3 forming the deliverystopper 3 c, axially opposed to the rotational stoppers 39 h. Theengagement between the rotational stoppers 39 h and the rotationalcounter stoppers 3 h is such that it allows a rotational dosing movementin a rotational direction, which causes a translational dosing movementof the dosage setting member 39 directed away from the delivery stopper3 c, but prevents a rotational dosing movement in the oppositerotational direction, in the front axial end position.

A further pair of rotational stoppers and rotational counter stoppers isprovided, which are formed and cooperate in basically the same way asthe stoppers 3 h and 39 h. The second pair of rotational stoppers arerotational stoppers 39 i which axially project from a rear abutting areaof the dosage setting member 39, and rotational counter stoppers 11 iwhich axially protrude from the facing stopper abutting area of the reartranslational stopper 11 c towards the dosage setting member 39. Therotational counter stoppers 11 i cannot be seen in FIG. 9 due to theirsmall dimensions. In the rear end position, the rear pair of rotationalstoppers 11 i/39 i prevents the piston rod 4 from being moved in theadvancing direction in response to a dosing movement by the dosagesetting member 39, directed against the rear translational stopper 11 c.

The height, or axial length, of all the rotational stoppers 3 h, 39 h,11 i and 39 i is adjusted to the thread pitch of the engaged dosingthread of the piston rod 4 and the dosage setting member 39. Therotational stoppers are axially sufficiently short that the rotationaldosing movement which moves the dosage setting member 39 away from therespective translational stopper 3 c or 11 c is not impeded.

When assembling the components of the reservoir module 10, the dosagesetting member 39 is screwed onto the piston rod 4 as far as a pre-setaxial position, as may be seen from FIG. 9. The piston rod 4, togetherwith the screwed-on dosage setting member 39, is then inserted into themechanism holder 3 from behind, until its blocking device 38 comes intoblocking engagement with the returning blocking means 6 of the pistonrod 4 and the engagement, secured against rotating, between therotational stoppers 39 h of the dosage setting member 39 and rotationalcounter stoppers of the mechanism holder 3 is established. Duringinsertion into the mechanism holder 3, the dosage setting member 39 isaxially and linearly guided by the mechanism holder 3 via the lockingengagement between the locking projections 3 g and the locking recesses39 g, until the dosage setting member 39 abuts the delivery stopper 3 cof the mechanism holder 3. In this front end position of the dosagesetting member 39 relative to the mechanism holder 3, the engagement,secured against rotating, between the rotational stoppers 3 h and 39 his established. In this state, the mechanism holder 3 and a reservoirpart 1, already fitted with a reservoir, are connected to each other.

In a following step, the rear casing section 11 of the assembled dosingand activating module 30 is slid onto the mechanism holder 3, whereinthe mechanism holder 3 and the rear casing section 11 can be centeredwith respect to each other due to the axial guides 3 d and theengagement elements 11 d of the rear casing section 11. Once centered,the mechanism holder 3 and the rear casing section 11 are axially andlinearly guided onto one another due to the guide engagement. In thecourse of sliding the rear casing section 11 onto the mechanism holder3, the dosing and activating element 32 comes into engagement, securedagainst rotating, with the dosage setting member 39, wherein centeringis also possible, using a linear guide corresponding to the axial guides3 d and the engagement elements 11 d.

The dosing and activating element 32 is in locking engagement with therear casing section in discrete rotational angular locking positions andin the locking engagement, i.e. in the respective rotational angularlocking position, is axially and linearly guided. The rotational angulardifference between two consecutive rotational angular locking positionscorresponds to one dosage unit. The linear guide between the mechanismholder 3 and the rear casing section 11 and the discrete rotationalangular positions of the dosage setting member 39 relative to themechanism holder 3 (locking projections 3 g and locking recesses 39 g)and the rotational angular locking positions of the dosing andactivating element 32 relative to the rear casing section 11 areadjusted to one another such that the two casing sections 1′ and 11 areslid linearly over one another in a rotational angular position. Thus,the dosage setting member 39 and the dosing and activating element 32are also aligned relative to one another for their engagement, securedagainst rotating, such that there is no relative rotating between thecomponents involved in dosing while the reservoir module 10 is connectedto the dosing and activating module 30.

With respect to the other details of assembling, in particular ofestablishing the latching engagement, and of the functionality of theinjection apparatus in accordance with the second embodiment, referenceis made to the description of first embodiment.

As shown in FIG. 21, rotational blocks may also be provided in theinjection apparatus of the first embodiment. The rotational blocksprevent undesired response movements by the piston rod 4 in the twoaxial end positions of the dosage setting member 9 of the firstembodiment. The two rotational blocks are formed in the same way as therotational blocks of the second embodiment. However, the rotationalcounter stoppers which in the second embodiment are formed on the casingsections 1′ and 11 are formed in the first embodiment by the blockingdevice 8 and the dosing and activating element 12. Thus, a number ofrotational stoppers 8 h are formed on the abutting side of the blockingdevice 8 axially facing the dosage setting member 9 and axially protrudetowards the dosage setting member 9. As the blocking device 8 is axiallyand immovably mounted by the front casing section 1′ and connected,secured against rotating, to the piston rod 4, a rotational block forthe rotational dosing movement between the piston rod 4 and the dosagesetting member 9 is also obtained, via the front pair of rotationalstoppers 8 h/9 h. A second pair of rotational stoppers is formed betweenthe dosage setting member 9 and the rear translational stopper 12 c. Asin the second embodiment, a number of rotational stoppers 12 i protrudeaxially towards the dosage setting member 9 from the abutting area ofthe translational stopper 12 c axially facing the dosage setting member9. As in the second embodiment, the dosage setting member 9 is providedon its rear side with rotational stoppers 9 i which, in the rear axialend position of the dosage setting member 9, engage with the rotationalstoppers 12 i. In the rear axial end position of the dosage settingmember 9, the rear pair of rotational stoppers 9 i/12 i only allows therotational dosing movement which causes a translational dosing movementof the dosage setting member 9 in the advancing direction.

In the foregoing description, embodiments of the invention, includingpreferred embodiments, have been presented for the purpose ofillustration and description. They are not intended to be exhaustive orto limit the invention to the precise form disclosed. Obviousmodifications or variations are possible in light of the aboveteachings. The embodiments were chosen and described to provide the bestillustration of the principals of the invention and its practicalapplication, and to enable one of ordinary skill in the art to utilizethe invention in various embodiments and with various modifications asare suited to the particular use contemplated. All such modificationsand variations are within the scope of the invention as determined bythe appended claims when interpreted in accordance with the breadth theyare fairly, legally, and equitably entitled.

1. An administering apparatus comprising: a) a casing; b) a drivendevice for performing a delivery stroke in an advancing direction alonga translational axis; c) a drive device for performing a deliverymovement; d) a dosage setting member coupled to the driven device suchthat a rotational dosing movement performed by the dosage setting memberand the driven device about the translational axis causes an axialtranslational dosing movement of the dosage setting member relative tothe driven device and the casing; e) a translational stopper positionedopposite and axially facing the dosage setting member in an axial endposition of the dosage setting member; and f) a rotational block which,in the end position of the dosage setting member, permits the rotationaldosing movement in a first rotational direction and blocks therotational dosing movement in a second rotational direction, wherein therotational block comprises at least one first rotational stopper and atleast one second rotational stopper, the first rotational stopper andthe second rotational stopper abutting against one another in the endposition of the dosage setting member, wherein the at least one firstrotational stopper is secured against rotating by the dosage settingmember and the at least one second rotational stopper is secured againstrotating by the casing.
 2. The administering apparatus of claim 1,wherein the rotational block prevents the dosage setting member frombeing pressed axially against the translational stopper by therotational dosing movement.
 3. The administering apparatus of claim 1,wherein the at least one first rotational stopper is carried by thedosage setting member and the at least one second rotational stopper iscarried by the casing.
 4. The administering apparatus of claim 1,wherein the at least one first rotational stopper is formed by thedosage setting member and the at least one second rotational stopper isformed by the casing.
 5. The administering apparatus of claim 1, whereinthe at least one first rotational stopper and the at least one secondrotational stopper protrude axially towards each other.
 6. Theadministering apparatus of claim 5, wherein the at least one firstrotational stopper and the at least one second rotational stopper areeach formed on one of two abutting areas which face one another axially.7. The administering apparatus of claim 1, wherein the at least onefirst rotational stopper is formed as a protrusion and the at least onesecond rotational stopper is formed as a recess, the protrusionprotruding into the recess to block the second rotational dosingmovement.
 8. The administering apparatus of claim 1, wherein the dosagesetting member comprises a thread and the driven device comprises athread, the engagement between the dosage setting member and the drivendevice being a threaded engagement of the dosage setting member threadand the driven device thread about the translational axis.
 9. Anadministering apparatus comprising: a) a casing; b) a driven device forperforming a delivery stroke in an advancing direction along atranslational axis to deliver a product dosage; c) a drive device forperforming a delivery movement to deliver the product dosage; d) adosage setting member coupled to the driven device such that arotational dosing movement performed by the dosage setting member andthe driven device about the translational axis causes an axialtranslational dosing movement of the dosage setting member relative tothe driven device and the casing; e) a translational stopper positionedopposite and axially facing the dosage setting member in an axial endposition of the dosage setting member; and f) a rotational block which,in the end position of the dosage setting member, permits the rotationaldosing movement in a first rotational direction and blocks therotational dosing movement in a second rotational direction, wherein therotational block comprises at least one first rotational stopper and atleast one second rotational stopper, the at least one first rotationalstopper and the at least one second rotational stopper abutting againstone another in the end position of the dosage setting member, whereinthe at least one first rotational stopper is formed as a unitary piecewith the dosage setting member and the at least one second rotationalstopper is formed as a unitary piece with the at least one translationalstopper.
 10. An administering apparatus comprising: a) a casing; b) adriven device for performing a delivery stroke in an advancing directionalong a translational axis; c) a drive device for performing a deliverymovement; d) a dosage setting member coupled to the driven device suchthat a rotational dosing movement performed by the dosage setting memberand the driven device about the translational axis causes an axialtranslational dosing movement of the dosage setting member relative tothe driven device and the casing; e) a translational stopper positionedopposite and axially facing the dosage setting member in an axial endposition of the dosage setting member; and f) a rotational block whichpermits the rotational dosing movement in a first rotational directionand blocks the rotational dosing movement in a second rotationaldirection, wherein the rotational block prevents the dosage settingmember from pressing axially against the translational stopper by therotational dosing movement, wherein the rotational block comprises atleast one first rotationally acting stopper and at least one secondrotationally acting stopper, the first rotationally acting stopper andthe second rotationally acting stopper abutting against one another inthe end position of the dosage setting member, wherein the at least onefirst rotationally acting stopper is secured against rotating by thedosage setting member and the at least one second rotationally actingstopper is secured against rotating by the casing.
 11. The administeringapparatus of claim 10, wherein the at least one first rotationallyacting stopper is mounted by the dosage setting member and the at leastone second rotationally acting stopper is mounted by the casing.
 12. Theadministering apparatus of claim 10, wherein the at least one firstrotationally acting stopper and the at least one second rotationallyacting stopper protrude axially towards each other.
 13. Theadministering apparatus of claim 10, wherein the at least one firstrotationally acting stopper is formed by the dosage setting member andthe at least one second rotationally acting stopper is formed by thecasing.
 14. The administering apparatus of claim 10, wherein the atleast one first rotationally acting stopper is formed as a protrusionand the at least one second rotationally acting stopper is formed as arecess, the protrusion protruding into the recess to block the secondrotational dosing movement.
 15. The administering apparatus of claim 10,wherein the dosage setting member comprises a thread and the drivendevice comprises a thread, the engagement between the dosage settingmember and the driven device being a threaded engagement of the dosagesetting member thread and the driven device thread about thetranslational axis.
 16. An administering apparatus comprising: a) acasing; b) a piston rod; c) a drive device for performing a deliverymovement to deliver a product dosage; d) a dosage setting member coupledto the piston rod such that a rotational dosing movement performed bythe dosage setting member about the translational axis causes an axialtranslational dosing movement of the dosage setting member relative tothe piston rod and the casing while the piston rod remains stationary;e) a translational stopper positioned opposite and axially facing thedosage setting member in an axial end position of the dosage settingmember; and f) a rotational block which, in the end position of thedosage setting member, permits the rotational dosing movement in a firstrotational direction and blocks the rotational dosing movement in asecond rotational direction, wherein the rotational block comprises atleast one first rotational stopper and at least one second rotationalstopper, the first rotational stopper and the second rotational stopperabutting against one another in the end position of the dosage settingmember, wherein the at least one first rotational stopper is securedagainst rotating by the dosage setting member and the at least onesecond rotational stopper is secured against rotating by the casing.